Churg-Strauss syndrome

Today we discussed Churg-Strauss syndrome, and some "tangents" related to it. A few concepts that came up:

Anatomic approach to weakness and associated features

Motor cortex: Upper motor neuron, involvement follows vascular territory. May see associated cortical findings (e.g. aphasia, apraxia, neglect, field defect). Usually unilateral

Internal capsule: Usually pure motor, with arm, leg, and possibly facial involvement. Unilateral. No cortical findings.

Brainstem: Crossed motor and sensory findings (i.e. lateralization of face and body may be different). Associated cranial nerve findings, level of consciousness may be affected

Spinal cord: Usually bilateral, often with a motor or sensory level.

Nerve root: Radiculopathy, usu at 1 level, often painful. Unilateral if physical compression If demyelinating (e.g. Guillain-Barre), bilateral leg weakness with areflexia

Peripheral nerve: Sensory findings associated, in dermatomal distribution. If general peripheral neuropathy, often length-dependent ("glove-stocking"), bilateral. If single nerves, this is "mononeuritis multiplex" or compression neuropathy.

Neuromuscular junction: No sensory findings, sometimes respiratory muscle involvement, with ptosis. Fatiguable if myesthenia gravis.

Myopathy: Bilateral, symmetrical, proximal. Sometimes CK elevation

Generalized: Think about metabolic abnormalities in addition to above (esp. PO4, K, Ca)

Mononeuritis multiplex differential diagnosis:
Essentially diabetes-related vs. vasculitis.
Common nerves involved in DM2: CN III, IV, VI, median nerve, peroneal nerve
Vasculitides that commonly cause mononeuritis multiplex: Churg-Strauss, polyarteritis nodosa, rheumatoid arthritis with vasculitic component

Eosinophilia Ddx
-parasitic infections
-allergic (asthma, allergy, eczema, AIN)
-vasculitic (Churg-Strauss, PAN)
-adrenal insufficiency
-hypereosinophilic syndrome (subset of hematologic malignancy; cardiac, CNS involvement)
-neoplastic (Hodgkin's lymphoma, CML, others)
-idiosyncratic drug reaction (common culprits are phenytoin, hydralazine, TMP/SMX, many others)
-cholesterol emboli

Churg-Strauss vasculitis

Click here for the American College of Rheumatology criteria for diagnosis

Asthma that is difficult to control is essentially an invariable feature of Churg-Strauss, and is one of the main differences between this and other similar vasculitides such as PAN and Wegener's granulomatosis.

Churg-Strauss should be suspected in patients with asthma (esp. adult onset) AND other organ involvement neurologic (esp. mononeuritis multiplex), gastrointestinal, pulmonary infiltrates, cardiac involvement (which would portend a poor prognosis), with eosinophilia.

Renal failure and glomerulonephritis is reported but less common than in other similar vasculitides (Wegner's, PAN)

Diagnosis is made by biopsy of affected organ or enough clinical criteria. 50% of patients have positive p-ANCA.

Treatment consists of high dose steroids and cytotoxic agents in high risk patients.

Link:

Click here for an excellent review of Churg-Strauss syndrome from Lancet